Combined separating and deflecting device for copying materials, more particularly for copying machines

ABSTRACT

An improved combined separating and deflecting device for copying materials, more particularly for copying machines, wherein a combination of two superimposed sheets is applied at a certain velocity, the improvement comprises that the sheet to be deflected has a lead and is guided between two cooperating separating rollers of which at least one is mounted pivotably and is driven at a higher peripheral speed that the speed of the transport means for the copying materials, comprising a guide adapted to be pivoted towards the sheet to be deflected in accordance with the state of engagement of the separating rollers, the guide guiding the other sheet in its direction and being fixed resiliently in its end positions by an overcentering device.

United States Patent Llmberger 5] Mar. 7, 1972 1541 COMBINED SEPARATINGAND DEFLECTING DEVICE FOR COPYING MATERIALS, MORE PARTICULARLY FORCOPYING MACHINES [72] Inventor: Walter Limberger,l-Iamburg-Poppenbuttel, Germany [73] Assignee: Lumoprint Zindler KG,Hamburg, Germany [22] Filed: Mar. 17, 1970 21 Appl. No.: 20,255

[30] Foreign Application Priority Data Mar. 19,1969 Germany ..P 19 13811.5

[52] US. Cl. ..271/64 [51] Int. Cl... B65h 29/64 [58] Field of Search..271/64, 18

[56] References Cited UNITED STATES PATENTS 3,304,081 2/1967 Limberger..271/64 X Primary Examiner-Joseph Wegbreit Assistant Examiner-Bruce H.Stoner, Jr.

Attorney-McGlew and Toren [5 7] ABSTRACT An improved combined separatingand deflecting device for copying materials, more particularly forcopying machines, wherein a combination of two superimposed sheets isapplied at a certain velocity, the improvement comprises that the sheetto be deflected has a lead and is guided between two cooperatingseparating rollers of which at least one is mounted pivotably and isdriven at a higher peripheral speed that the speed of the transportmeans for the copying materials, comprising a guide adapted to bepivoted towards the sheet to be deflected in accordance with the stateof engagement of the separating rollers, the guide guiding the othersheet in its direction and being fixed resiliently in its end positionsby an overcentering device.

11 Claims, 4 Drawing Figures COMBINED SEPARATING AND DEFLECTING DEVICEFOR COPYING MATERIALS, MORE PARTICULARLY FOR COPYING MACHINESDESCRIPTION Known constructions of combined separating and deflectingdevices for copying materials, particularly for copying machines inwhich a leading edge of a sheet is deflected, have the disadvantage thatthe materials must be treated comparatively roughly if the sheet is tobe pulled off with sufficient force. However, an excessive pulling offaction may be transferred to upstream transport means and may causedamage to the materials. Apart from that with known pairs of separatingrollers, there occur comparatively large mass forces which may lead tovibration. Although it is advantageous to deflect the sheet to bedeflected substantially at a right angle to the guide, the pivoting pathof the separating roller arrangement must be comparatively large, sothat also the lead of the one sheet must be comparatively large even ifthe separating rollers run at a considerable speed.

Copying materials, the layers of which adhere, may be joined togetherfairly strongly so that a separation cannot be guaranteed if the leadingedge passes about the end of the guide track.

It is an object of the invention to provide a combined separating anddeflecting device, using separating rollers with lower mass forces.

It is a further object of the invention to provide a separating anddeflecting device of the kind hereinbefore mentioned, in which theseparating rollers run at a lower speed than in hitherto known devices.

It is yet another object of the invention to provide a separating anddeflecting device in which the separating rollers have a definitestarting position, facilitating the application of the leading edge andthereby a shorter lead.

It is yet another object of the invention to provide a combinedseparating and deflecting device in which the materials arepreliminarily loosened by action thereon within the guide track prior tothe deflection of the leading sheet.

According to the invention, the guide face forms a guide element guidingthe other sheet in its direction, and is retained by a spring mounted inspaced-apart relationship behind the pivoting axis of the guide face onthe guide face and resiliently fixes the guide face in its terminalpositions, wherein during the pivoting the guide face passes, inconjunction with the spring, through an over center point.

By using the spring in an over center arrangement it is possible for thecombination of the two superimposed sheets to run with its trailing endbetween the transport rollers of a copier, even after the leading edgehas been gripped by the separating rollers. The edge of the guide movingelastically under the action of the spring slides along the underside ofthe sheet to be deflected in the direction opposite its advance, so asto produce particularly favorable conditions for separating the othersheet which is being deflected into its new direction by the guide.

Preferably, a movable cage of separating rollers forms a locking elementfor a biased drive, acting by means of a cam control on the guide,causing the same to be pivoted or to pass through the over center afterits release. This provides a simple and effective solution for thecollaboration of the separating rollers and the guide.

In the preferred embodiment, the cam control is a single speed drive,the speed of which matches the throughput speed of one sheet length,wherein the cam control pivots during its revolution the guide first inthe deflecting or separating position and later into the startingposition. This achieves an automatic resetting in conjunction with theover center arrangement, and this is essential because a continuousforce may be provided for pivoting the guide to its end position in thenew direction, so as to provide a stripping effect.

According to a particularly preferred embodiment of the invention, thespeed of the single speed drive is so matched to the throughput speed ofa sheet length that during the passage of a sheet the guide is pivotedto and fro several times, providing a multiple and differentialdeflection of the combination of the superimposed sheets.

Preferably the sheet to be deflected is pulled off by the separatingrollers substantially at a right angle from the edge of the pivotedguide.

Preferably, the cam control is provided with two cam tracks, the cams ofwhich act through spring loaded plungers on one or the other side of thepivot on the guide in order to pivot or to reset the same.

In a particularly preferred embodiment, the single speed drive of thecam control consists of a drive disk or pulley with a concavecircumferential recess and a roller freely revolving in the concaverecess, but engaging the periphery of the drive disk when the same isdeflected. In this embodiment an actuating spring, mounted on a crank,is tensioned when the drive roller is aligned to the recess, whilst thedrive disk is retained by a locking device formed by the separatingroller cage. This arrangement provides a particularly advantageouscombination between the function of the separating roller device and thesingle speed drive.

Preferably, when the separating roller device is relieved the lockingdevice engages into a step in the periphery of the drive disk, whereinthe association between locking device and step is such that the springis held under tension when these two parts interengage.

Preferably, a separating roller is mounted on a pivoting lever of theseparating roller cage in arcuate oblong holes of a bearing block; thelever is pivotable about the actuating shaft of the other separatingroller and forms the locking device. This provides a certain impulse forunlocking the single speed drive.

In a particularly preferred embodiment, the guide carries, spaced apartfrom the separating rollers and preferably behind the pivot, a guideroller under which the sheets are guided. This guide roller has theaction of deflecting the assembly of two sheets from its normal path,and thereby achieving a preliminary detachment. The arrangement of afreely revolving roller prevents friction, whilst producing a separationby guiding the sheets along a curved surface. Preferably an arcuateguide face is provided at the bearing mountings of the guide roller,extending obliquely from the guide face to the separating rollers andimpinging on the sheets when the guide is deflected. This achieves arepeated deflection in front of the guide roller; obviously a furtherdeflection is accomplished in an upstream pair of transport rollers ofthe apparatus, so that separation is reliably achieved. In thisconnection it should be mentioned that, so long as the combination oftwo sheets is still guided by this pair of transport rollers, the springaccording to the invention, acting on the guide, ensures the positiveguiding action under gradual increase of deflecting actions.

The invention will be further described with reference to theaccompanying drawings, showing an embodiment thereof and in which:

FIG. 1 is a side elevation showing the parts essential for thefunctional explanation of the invention;

FIG. 2 is an end elevation of the single speed drive, viewed from theright-hand side, with the drive roller omitted;

FIG. 3 shows diagrammatically a copier and explains the arrangement ofthe separating and deflecting device according to the invention;

FIG. 4 is a diagram showing the the drive.

FIGS. 1 and 2 show the essential features of the invention. FIG. 3shows, by way of example, the arrangement in a copier and will bediscussed first.

A copying section 54 contains, for example, a path 55 for inserting andpassing through an original in the direction indicated by an arrow 56.By means of switches, well known in the art, the original releases asheet of copying material from a stack 57, on to which the passingoriginal is exposed at 58 by port devices, the application of anotherreceiving sheet from a stack 61, forming a combination of two sheets at62; this combination entersin the direction of the arrow 4 a unit 65which will be explained further below in detail with reference toFIG. 1. At the inlet of this unit is a first pair of transport rollers2, 3, at the outlet a second pair of transport rollers 49, or the pairof separating rollers 8, 9, underneath which is a trough 66 adapted toreceive the deflected sheet, whilst the other sheet enters a dryingsection 45 which will also be explained with reference to H6. 1.

Referring now to FIG. 1, the wall portion 1 is merely a mounting wall ofthe frame with two mounting walls, between which the elements shown arearranged. The distance between the mounting walls corresponds to thewidth of the copying material. For example, the guide 5 and the rollers2, 3, 49, 50, 8, 9 have an appropriate width.

Bearing means are arranged in these wall portions, the outsides of whichmay be provided with drive means such as motors, gears and the like,adapted to drive the part in the direction of the arrows shown.

The frame with the wall 1 is preferably integral with the unit 55 to 62and is arranged at the end of an apparatus, adapted to deliver twosheets.

A pair of transport rollers 2, 3 is mounted in the wall section 1; theserollers are driven, by means not shown, in the direction of the arrowsindicated. By means of this pair of transport rollers a combination oftwo sheet is applied in the direction of arrow 4, extending tangentiallybetween the two rollers 2, 3; of these two sheets, the lower leads theupper sheet. These sheets are sheets of copying material coming from adeveloping device and in this case, a negative or transfer sheet must beseparated from a positive or receiving sheet which is to betreatedfurther. In view of a preceding chemical reaction, these sheets mayfirmly adhere to each other.

A guide 5 extends parallel to the direction of advance of thecombination of two sheets in the direction of the arrow 4; in order toensure the uninhibited passage, the end 6 of the guide, facing rollers2, 3, is curved. This guide is freely pivotable about a pivot 7 mountedin the frame 1, and extends, as viewed from the rollers 2, 3, beyond thepivot and is directed towards the zone of contact between the separatingrollers 8, 9. In this position, the end cam of the guide, facing theseparating rollers, abuts on a plunger 11. This plunger rests in a guide12, mounted on the frame 1, on a cam 13 of cam disk 14 which isstationery and locked in the starting position. The end of the guide ispulled towards the plunger 11 by a spring 15 which is fixed to the frameas at 16, and to the guide 5 as at 17 behind the pivot 7. The guide 5 isadapted to be pivoted into a position 5'. In this latter position, theguide is retained by a plunger 18, guided in a guide 19, mounted on theframe 1 and resting on a cam disk 20 with a cam 21, which does not atthis moment make contact with the plunger. Both plungers 11 and 18 runon the associated cam disks by means of rollers 22, 23. The plungers areequipped with annular abutments 24, on which rest springs 26, 26'; theother ends of the springs rest on the guides 12, 19 and urge theplungers against the cam disks.

The separating rollers 8, 9 are guided in a bearing block 27 located inthe main frame 1 and having an opening 27' under the separating rollersfor removing one sheet. The shafts or spindles 28, 29 of the separatingrollers are located in a pivoting lever 30 of a separating roller cage;the shaft 29 which extends into the bearing block 27, formssimultaneously the pivot for the pivoting lever 30. The shaft 28 extendsbeyond the cage with the pivoting lever 30 and is located in oblongholes 31 of the bearing block, extending concentrically to the shaft 29,permitting the pivoting lever to be pivoted along this oblong hole. Theseparating rollers are driven by a separate drive, not shown in detailin the drawing, in the direction of the arrows at a circumferentialspeed which is greater than that of the transport rollers 2, 3.

The pivoting lever 30 extends at an angle and forms a locking bolt 32,the end of which has a hook 33. This hook engages in the startingposition into a step 34 of a disk 35 of a single speed drive which alsocomprises the cam disks 14, 20. The single speed drive is mounted freelyrotatably on the frame 1 by means of a shaft 36. The mountings areindicated at 37, 38; where the drive means are arranged, as in thedrawing, under the guide 5 the mounting 37 corresponds to a mountingdevice in the frame member shown in FIG. 1. The single speed drive has adrive disk 39 with a circumferential recess 40. In the inoperativeposition, a drive roller 41, mounted in the frame and having a curvaturematching that of the recess 40, is located concentrically thereto. Thearrangement is such that the periphery of the drive disk 39 makesengagement with the drive roller adjacent to the recess 40. The driveroller 41 is driven in the sense indicated by an arrow by a continuousdrive which may be, for example, the same drive as that actuating thetransport rollers 2, 3. The bearing block 27 may be affected by a weakcompression spring urging the hook 33 against the periphery of the disk35. However, the weight of the bearing block, 27 is sufficient toproduce this contact pressure by pivoting about the shaft 29.

In addition, the disk 35 carriers a crank arm 42 to which is fitted aspring 43, the other end of which is mounted on the frame as at 44.

In the starting position fixed by the locking bolt 32, the spring 43passes over the top of the disk 35 in the direction of rotation, and istensioned so that, on release, the spring 43 actuates the single speeddrive.

The positive or receiving sheet is to be transported into a dryingsection, shown generally at 45. This section comprises thermal radiators46 under a guide track (arrow 47) and a reflector 48 above the same. Theparts 46 and 48 are mounted between pairs of transport rollers 49, 50which may be driven, for example, by the same drive as the transportrollers 2,3 in the direction indicated by the arrows.

A guide roller 52 is mounted freely rotatably between the pivot 17 andthe end 6 on the guide 5 between bearing lugs 51. The spacing from theguide is so large that the combination of the two sheets may passwithoutobstruction under the guide roller 52. The bearing lugs 51 carry also anupwardly arcuate guide face 53 facing the transport rollers 2, 3 andextending across the guide 5.

Concerning the position 5 and 5 and the mounting 17 of the spring 15relative to the pivot 7, it may be seen that, when the guide passes fromone position to the other, it must pass across an additional tensioningposition of the spring 15, forming a type of over center arrangement,the end positions of whichare defined by the plungers 11 and 18. In thisconnection it should be noted that, for passing through an over center,only an initial impulse is necessary which exceeds the over centerposition, whilst the movement into the final position is accomplished bythe spring 15.

If the leading edge of the lower sheet of a combination of two sheetsadvancing on the guide under the guide roller 52, i.e., the leading edgeof the sheet located on the guide 5, reaches the position between theseparating rollers 8, 9, the higher driving speed of these rollersproduces a force which rotatesthe separating roller cage with thepivoting lever 30 in a clockwise direction about the shaft 29 (inaccordance with the oblong hole 31). In consequence the locking bolt 32,with its hook 33, is disengaged from the step 34 and the spring 43rotates the single speed drive in an anticlockwise direction, therebyengaging the drive roller 41 with the periphery of the drive disk 39 andmoving the same. During this movement, the cam 13 on the cam disk 14actuates the plunger 11 and pivots the guide through the over centerposition, causing the edge at the end 10 of the guide to rest on thesheets, and to press, by means of spring 15, so long under increasingdeflection of the lower sheet, now gripped by the separating rollers 8,9, until the guide has reached the position 5. Meanwhile, the cam 13 haspassed under the roller 22. The end position parallel to the arrow 47 isachieved by means of the plunger 18 associated with the cam disk. Inconsequence of the pivoting, the end of the guide face 53 makes contactwith the combination of sheets which are deflected as indicated by thedash-dot line 54a. It follows, therefore, that a first deflection occursat the roller 2, a second deflection along the guide face 53, and athird at the guide roller 52. The lower sheet is deflected at the edgeof the end of the guide substantially at a right angle, and removedtowards the bottom by the pair of separating rollers 8, 9.

According to the dimensioning of the single speed drive, but certainlynot later than after the trailing edge of the combination of sheets hasleft the transport rollers 2, 3, the separating roller cage and thepivoting lever 30 return in the starting position, so that the hook 33of the locking bolt engages the step 34 and stops the drive 35, 39, 14,in the position shown in the drawing, with the spring 43 tensioned.

Although it has been said that the time of rotation of the single speeddrive, that is to say the circumference of the drive disk 39 relative tothe rotational speed of the drive roller 41 matches the throughput timeof one sheet length, this condition is not essential. 1f the cycle ofthe single speed drive is shorter, the guide 5 is pivoted to and froseveral times during the passage, thereby improving the separationbetween the two sheets. It must here be remembered that the applicationof the force is controlled in this case by the spring 15.

This may be effected in that manner that the distance between the firstpair of transport rollers 2, 3 and the separating rollers 8, 9corresponds only to a fraction of the length of a sheet. In this mannerthe locking devices 33, 34 would remain disengaged after the singlespeed drive has performed one revolution. It is also possible to providethe circumferences of the disks 14, 20 with several cams such as 13, 21in order to provide several actuations during one revolution.

Where the drive roller 41 has a fixed rotational speed, certain speedassociations may be accomplished by suitably dimensioning the diametersof the disks 20, 35.

It is obvious that the spindles 67, 68 of the rollers 2, 3, the spindles69, 70 of the rollers 49, spindles 71, 72 of the rollers 50, the shaft29, the pivot 7 of the guide 5, and the shaft 73 of the drive roller 41,are mounted in spaced-apart relationship between the wall 1 and passthrough a wall portion where they engage with suitable drive elements.

The drive elements are shown in H0. 4. There may be provided a mainmotor 74 adapted to be switched through a circuit 75 which also containsthe light source 76. The drive motor actuates first drive means 77, atransmission to which are connected the rollers 2, 3, 49, 50 andcorresponding transport rollers in the exposure and developing sections.A transmission 78, changing the transmission ration, connects seconddrive means for the separating roller 9. By means of a furthertransmission 80, a separate drive 81 is driven from the first drivemeans 77 for operating the drive roller 41.

lclaim:

I. An improved device for separating and deflecting two sheets, moreparticularly sheets of copying material, in a copying machine, whereinthe sheets are guided one superposed on the other along a path for thecopying materials with the leading edge of one sheet projecting beyondthe leading edge of the other sheet, a guide path for the two sheetsdivided at a downstream point into two separate paths one for each ofthe sheets, a first pair of transport rollers located at the upstreamend of said guide path, a second pair of transport rollers at the startof one of the separate paths with imaginary lines through both spindlesof each said first and second pairs of transport rollers intersectingand forming an angle therebetween, a frame in which said pairs oftransport rollers are rotatably mounted, first drive means in said framedriving at least one roller of each said pair of transport rollers at acertain circumferential speed, a separating device including twoseparating rollers positioned at the start of the other one of theseparate paths, second drive means for said separating rollers fordriving said separating rollers at a higher circumferential speed thanthe circumferential speed of said pairs of transport rollers driven bysaid first drive means, a guide located between said first pair oftransport rollers and said separating rollers and mounted pivotally insaid frame, a pivot for said guide in said frame so that said guide ispivotally displaceable between two end positions, and a spring attachedunder tension at one end to said frame and at its other end to saidguide at a position spaced from said pivot for said guide, wherein theimprovement comprises that said separating rollers are arranged so thatthey make contact substantially along a line extending perpendicularlyto the line connecting the axes of said first pair of transport rollerswhich line extends through the point of contact of said first pair oftransport rollers, at least one of said separating rollers is rotatablymounted in said frame, said pivot for said guide is located between thepoint of attachment of said spring to said frame and the point ofattachment of said spring to said guide for fixing said guideelastically in its two end positions, a first abutment means forcooperating with said guide and defining one of its end positions, asecond abutment means for cooperating with said guide and defining itsother end position, and adjusting means in operative engagement betweensaid separating rollers and said first and second abutment means so thatwhen the leading edge of the one sheet which projects beyond the leadingedge of the other sheet has been gripped by said separating rollers, areacting force resulting from the higher circumferential speed of saidseparating rollers pivotally displaces said guide about said pivot fromone end position, aligned substantially between said first pair oftransport rollers and said separating rollers, into the other endposition extending substantially perpendicularly to the line connectingthe axes of said second pair of transport rollers, with said guidepassing in conjunction with said spring through an over center pointduring each pivotal displacement and in which passage through the overcenter point the tensioning of said spring is greater than in the endpositions of said guide.

2. A device as set forth in claim 1, wherein at least one saidseparating roller is mounted movably concentrically to the axis of saidother separating roller, a lever is mounted pivotably about the axis ofsaid other separating roller, the axis of the one said separating rollerbeing mounted in the frame, and the axis of said other separating rollerbeing provided in said lever, and said lever having an extension whichcooperates with said adjusting means which is in operative engagementwith said abutment means.

3. A device as set forth in claim 2, wherein said movably mountedseparating roller has its axis mounted in said lever, a bearing blockhaving arcuate oblong holes is mounted on said frame, the axis of saidmovably mounted separating roller is mounted in the arcuate oblong holesof said bearing block, and the oblong holes are concentric to the axisof the other said separating roller, the axis of which forms the driveshaft.

4. A device as set forth in claim 1, wherein said lever forms aseparating roller cage as bearing block for said separating rollers andsaid extension forms a locking element with said adjusting means, aspring for actuating said adjusting means, said adjusting meansincluding a step for engagement with said locking element and cams whichsuccessively cooperate with said abutment means.

5. A device as set forth in claim 1, wherein said first and secondabutment means are plungers, fixed guide means for mounting saidplungers in said frame so that their ends remote from said actuatingmeans act on said guide on opposite sides of said pivot, said adjustingmeans having cam tracks,an annular abutment positioned on each saidplunger, a spring arranged between each said fixed guide means annularabutment on said plungers for urging said plungers away from said guidetowards said cam tracks on said adjusting means, and each said cam trackhaving at least one cam which cooperates with one end of one of saidplungers.

6. A device as set forth in claim 1, wherein said adjusting meanscomprises a single speed drive including disks mounted in said frame andprovided with actuating cams, said first abutment means are actuatedafter release of said adjusting means by the leading sheet of the onesheet entering between said separating rollers for moving said guidefrom one end position into the other end position, and later said secondabutment means are actuated by the engagement of one of said actuatingcams, for returning said guide into its starting position.

7. A device as set forth in claim 6, wherein said single speed drive isconstructed for a multiple revolution during the passage of one sheetlength, and said guide is arranged to be pivoted to and fro severaltimes during the passage of the sheets.

8. A device as set forth in claim 1, wherein said adjusting meanscomprise engaging devices arranged to interengage a drive disk with aconcave circumferential recess and a drive roller which freely revolvesin said concave recess but makes driving engagement with the peripheryof said drive disk when the same is rotated, said drive disk contains aeccentrically arranged crank, an actuating spring attached at one end tosaid crank and at its other end to a fixed device on said frame, saidactuating spring is tensioned when the concave recess is aligned to saiddrive roller and said engaging devices are arranged relative to saiddrive disk so that the concave recess thereof is aligned to said driveroller when said engaging devices interengage.

9. A device as set forth in claimr8, wherein one of said engagingdevices comprises a lever having a hook and the other said engagingdevice comprises a disk connected to said drive disk and having a steparranged to receive said hook so that when the reaction force at saidseparating rollers is relieved said hook rests on the periphery of saiddisk in engagement with the step thereon, two other disks fixed to saiddrive disk and having cams thereon, and a common shaft positioned insaid frame and mounting said drive disk and said disks fixed to saiddrive disk.

10. A device as set forth in claim 1, wherein said guide is provided inthe center zone along its sides with mounting lugs spaced apart from theend facing said separating rollers, a a

freely rotatable guide roller supported by said mounting lugs inspaced-apart relationship from the upper side of said guide, saidmounting lugs are arranged on that side of said pivot of said guidewhich is adjacent to said first pair of transport rollers.

11. A device as set forth in claim 10, including arcuate guide facesupported on said mounting lugs and extending obliquely from said guidetowards its end adjacent said first pair of transport rollers.

1. An improved device for separating and deflecting two sheets, moreparticularly sheets of copying material, in a copying machine, whereinthe sheets are guided one superposed on the other along a path for thecopying materials with the leading edge of one sheet projecting beyondthe leading edge of the other sheet, a guide path for the two sheetsdivided at a downstream point into two separate paths one for each ofthe sheets, a first pair of transport rollers located at the upstreamend of said guide path, a second pair of transport rollers at the startof one of the separate paths with imaginary lines through both spindlesof each said first and second pairs of transport rollers intersectingand forming an angle therebetween, a frame in which said pairs oftransport rollers are rotatably mounted, first drive means in said framedriving at least one roller of each said pair of transport rollers at acertain circumferential speed, a separating device including twoseparating rollers positioned at the start of the other one of theseparate paths, second drive means for said separating rollers fordriving said separating rollers at a higher circumferential speed thanthe circumferential speed of said pairs of transport rollers driven bysaid first drive means, a guide located between said first pair oftransport rollers and said separating rollers and mounted pivotally insaid frame, a pivot for said guide in said frame so that said guide ispivotally displaceable between two end positions, and a spring attachedunder tension at one end to said frame and at its other end to saidguide at a position spaced from said pivot for said guide, wherein theimprovement comprises that said separating rollers are arranged so thatthey make contact substantially along a line extending perpendicularlyto the line connecting the axes of said first pair of transport rollerswhich line extends through the point of contact of said first pair oftransport rollers, at least one of said separating rollers is rotatablymounted in said frame, said pivot for said guide is located between thepoint of attachment of said spring to said frame and the point ofattachment of said spring to said guide for fixing said guideelastically in its two end positions, a first abutment means forcooperating with said guide and defining one of its end positions, asecond abutment means for cooperating with said guide and defining itsother end position, and adjusting means in operative engagement betweensaid separating rollers and said first and second abutment means so thatwhen the leading edge of the one sheet which projects beyond the leadingedge of the other sheet has been gripped by said separating rollers, areacting force resulting from the higher circumferential speed of saidseparating rollers pivotally displaces said guide about said pivot fromone end position, aligned substantially between said first pair oftransport rollers and said separating rollers, into the other endposition extending substantially perpendicularly to the line connectiNgthe axes of said second pair of transport rollers, with said guidepassing in conjunction with said spring through an over center pointduring each pivotal displacement and in which passage through the overcenter point the tensioning of said spring is greater than in the endpositions of said guide.
 2. A device as set forth in claim 1, wherein atleast one said separating roller is mounted movably concentrically tothe axis of said other separating roller, a lever is mounted pivotablyabout the axis of said other separating roller, the axis of the one saidseparating roller being mounted in the frame, and the axis of said otherseparating roller being provided in said lever, and said lever having anextension which cooperates with said adjusting means which is inoperative engagement with said abutment means.
 3. A device as set forthin claim 2, wherein said movably mounted separating roller has its axismounted in said lever, a bearing block having arcuate oblong holes ismounted on said frame, the axis of said movably mounted separatingroller is mounted in the arcuate oblong holes of said bearing block, andthe oblong holes are concentric to the axis of the other said separatingroller, the axis of which forms the drive shaft.
 4. A device as setforth in claim 1, wherein said lever forms a separating roller cage asbearing block for said separating rollers and said extension forms alocking element with said adjusting means, a spring for actuating saidadjusting means, said adjusting means including a step for engagementwith said locking element and cams which successively cooperate withsaid abutment means.
 5. A device as set forth in claim 1, wherein saidfirst and second abutment means are plungers, fixed guide means formounting said plungers in said frame so that their ends remote from saidactuating means act on said guide on opposite sides of said pivot, saidadjusting means having cam tracks, an annular abutment positioned oneach said plunger, a spring arranged between each said fixed guide meansannular abutment on said plungers for urging said plungers away fromsaid guide towards said cam tracks on said adjusting means, and eachsaid cam track having at least one cam which cooperates with one end ofone of said plungers.
 6. A device as set forth in claim 1, wherein saidadjusting means comprises a single speed drive including disks mountedin said frame and provided with actuating cams, said first abutmentmeans are actuated after release of said adjusting means by the leadingsheet of the one sheet entering between said separating rollers formoving said guide from one end position into the other end position, andlater said second abutment means are actuated by the engagement of oneof said actuating cams, for returning said guide into its startingposition.
 7. A device as set forth in claim 6, wherein said single speeddrive is constructed for a multiple revolution during the passage of onesheet length, and said guide is arranged to be pivoted to and froseveral times during the passage of the sheets.
 8. A device as set forthin claim 1, wherein said adjusting means comprise engaging devicesarranged to interengage a drive disk with a concave circumferentialrecess and a drive roller which freely revolves in said concave recessbut makes driving engagement with the periphery of said drive disk whenthe same is rotated, said drive disk contains a eccentrically arrangedcrank, an actuating spring attached at one end to said crank and at itsother end to a fixed device on said frame, said actuating spring istensioned when the concave recess is aligned to said drive roller andsaid engaging devices are arranged relative to said drive disk so thatthe concave recess thereof is aligned to said drive roller when saidengaging devices interengage.
 9. A device as set forth in claim 8,wherein one of said engaging devices comprises a lever having a hook andthe other said engaging device comprises a disk connected to said drivedisk and having a step arranged to receive said hook so that when thereaction force at said separating rollers is relieved said hook rests onthe periphery of said disk in engagement with the step thereon, twoother disks fixed to said drive disk and having cams thereon, and acommon shaft positioned in said frame and mounting said drive disk andsaid disks fixed to said drive disk.
 10. A device as set forth in claim1, wherein said guide is provided in the center zone along its sideswith mounting lugs spaced apart from the end facing said separatingrollers, a freely rotatable guide roller supported by said mounting lugsin spaced-apart relationship from the upper side of said guide, saidmounting lugs are arranged on that side of said pivot of said guidewhich is adjacent to said first pair of transport rollers.
 11. A deviceas set forth in claim 10, including arcuate guide face supported on saidmounting lugs and extending obliquely from said guide towards its endadjacent said first pair of transport rollers.